.header {
  padding: 20px;
  text-align: center;
  background-color: #f4f4f4;
  border-radius: 5px 5px 0 0;
}

.header h1 {
  margin: 0 0 15px 0;
  color: #333;
}

.todo-input {
  width: 100%;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 16px;
  box-sizing: border-box;
}

.todo-input:focus {
  outline: none;
  border-color: #4caf50;
  box-shadow: 0 0 5px rgba(76, 175, 80, 0.3);
}